Process for the manufacture of imidazolines containing at least 10 carbon atoms



Patented Apr. 25, 1939 UNlTED STATE-S PROCESS FOR 1THE MANUFACTURE OF IMIDAZOLINES CONTAINING AT LEAST 10 CARBON ATOMS Edmund Waldmann, Klosterneuburg, and August Chwala, Vienna, Austria, assignors to I. G. Farbenindustrie Aktiengesellschaft, Frankforton-the-Main, Germany No Drawing. Application August 3, 1936, Serial' No. 94,120. In Austria April 4, 1936 11 Claims.

This invention relates to the manufacture of imidazolines containing aliphatic radicals of high molecular weight as substituents at the 2-carbon atom by heating with a fatty acid or a carboxylic acid of high molecular weight to high temperatures, preferably to temperatures lying between 200 and 300 C., a mixture consisting on the one hand of 'a base having a primary amino-group and a second primary or secondary amino-group, which are in 1:2-position to each other, the'two carbon atoms in 1:2-position being linked by a single bond, and on the other hand a salt of such base formed from a strong acid.

Suitable bases having a primary amino-group and a second primary or secondary amino-group in 1:2-position to each other are ethylenediamine; products such as diethylenetriamine, triethylenetetramine, tetraethylenepentamine; ,homologues of ethylenediamine such as 1:2-propylenediamine, 2 B-butylenediamine, N-methylethylenediamine.

Suitable strong acids for forming the salts are in particular mineral acids, such as hydrochloric acid, hydrobromic acid, sulfuric acid, and the like.

Suitable fatty acids of high molecular weight are in general aliphatic acids containing more than 8 carbon atoms, for instance caprylic acid, lauric acid, stearic acid, palmitic acid, oleic' acid, also mixtures of these acids obtainable by saponifying natural fats like olive oil, tallow, palm oil; also cycloaliphatic acids such as naphthenic acids and the like. I

Instead of the fatty acids there maybe used suitable derivatives thereof such as esters, amides, anhydrides or halides; according to the selection of the derivative to be used, the simultaneous use of the free base or the salt of the base may, if desired, be omitted, for in the case of halides the suitable mixtures leading to the desired result are formed, due to the mineral acid becoming free, in the course of the acylation.

Quite generally, the new process consists in heating with a product selected from the group consisting of fatty acids of high molecular weight andthe salts, amides, halides and esters thereof, a mixture consisting on the one hand of a base which is substituted at two carbon atoms adjacent to each other by an amino-group each, of which amino-groups one contains two hydrogen atoms and the other at least one hydrogen atom, and on the other hand of a salt of such basewith a strong acid, the heating being carried out at a high temperature.

The procedure may also be such that first of all the salt of the mono-acyl compound is prepared. The process then consists in heating to a high temperature a salt formed froma strong acid and such a diamine mono-acylated with a fatty acid of high molecular weight, in which the two amino groups are bound to two carbon atoms adjacent to each other, i one of which amino groups containing two hydrogen atoms'and the other at least one hydrogen atom.

In the preferred mode of operating, the mixture made in accordance with the invention is heated to a temperature of 250-290 C. If, for example, there is used a quantity of lauric acid, ethylenediamine and ethylenediaminehydrochloride the hydrochloride which forms a sediment dissolves very quickly in this interval of temperature, even with only gentle stirring, and at the same time causes formation of the undecyl-imidazoline-hydrochloride." This reaction may also beconducted ata temperature lower than 250 C. by heating for a longer period. The use of a vacuum during the second half of the condensation is useful.

When the condensation to the imidazoline derivative starts from a mixture of fatty acid amine and aminehydrochloride, the three components of the mixture are advantageously selected so that for 1 mole of the fatty acid or its derivative there are at least 1 mole each of the diamine and the salt-like. bound mineral acid.-

In using 1 mole of lauric acid therefore, there should be mole ethylenediamine and moleethylenediaminehydrochloride, correspo'nding with the equation: Guano0m+nNmqmNm+tmimammal-2uo1)= NHCH:.

(nllnC N *n5 and there is obtained the hydrochloride of undecylimidazoline.

If, however, the parent materialIs-the monolauroylethylenediaminehydrochloride which already contains in itself ,per 1 mole fatty acid 1 mole of ethylenediamine and 1 mole of hydrochloric acid, it sufliceszto heat this hydrochloride by itself to about 250-300 C. in order to obtain an excellent yield of the-hydrochloride of undecylimidazoline. This reaction can also be carried out with the other mono-acyl-derivatives which are obtained from the diamines and the fatty acids of high molecular weight mentioned in paragraphs 2 and 4 of this specification.

Under the effect of the aminesalt, particularly the hydrochloride, one finds at comparatively high temperature of reaction evidently an elimination of the acid amide-at first formed (as may be seen particularly clearly from the example of dilauroylethylenediamine) and then a combinationof the eliminated material directly to the imidazolinehydrochloride. Philipps (Journal of the Chemical Society of London, 1928, page 2393 and following; Chemisches Zentralblatt 1928, vol.

2, page 2466) is of opinion that the formation of benzimidazoles or irnidazolines from the acylderivatives of the corresponding diamines by boiling with hydrochloric acid occurs 01 itself in such a manner that the acid amide is first saponified and the eliminated portion united directly to the benzimidazol or imidazoline.

These imidazolines of high molecular weight in the form of their salts are freely soluble in water; solutions foam and have good capillary active properties. They may be used with advantage I or improving dyeingson vegetablefibers.

Sulfo-groups maybe introduced in their molecules by the methods which have become known from French Specification No. 796,917. These imidazoline-sulfonates of high molecular weight are also valuable as wetting; foaming, washing, emulsifying and dispersing agents. They are valuable as assistants in the textile industry.

The following examples illustrate the invention the parts being by weight:

Example 1 Into a stirring vesselprovided with a th'ermometer and an inverted condenser there are charged- I r Parts Stearic acid 284 Ethylenediaminehydrochloride 93 Ethylenediaminehydrate .56

The mixture is heated while stirring to C. and the temperature is raised within 9.0 minutes to 185 C., whereby between 170 and l85-C..a'small proportion of a clear liquid distills (ethylenediaminehydrate and water). Thetmixture is now heated within 30 minutes to 230 C. .and then within 15 minutes to 290 C. The mass is kept for a short time at this temperature, which may be raised to 300 C. until a sample of the mass,

tested with water, shows that it is soluble inwater to a clear solution; the heating then interrupted and the mass cooled. The brownish mass, which is crystalline when cold, consists almost exclusively of heptadecylimidazolinehydrochloride.

A free base may be separated in known manner by dissolving the hydrochloride with water and liberating the base with an alkali-hydroxide which can then be directly filtered or extracted by means of benzene. For further purification the product may be crystallized from a mixture of 3 parts of methyl alcohol and 1 part of water,

whereby .Z-heptadecylimidazoline is obtained in crystalllnescales melting at-94-'95 C.

Example 2 In an apparatus such as 'is described in Example 1 :there is heateda mixture of- Parts Laurie acid Ethylenediaminehydrate- 40 Ethylenediaminehydrochloride 60 .in manner described in the same example. As soon .as a sample of the mass is clearly soluble in water, -the heating is interrupted. On cooling, the mass solidifies in crystalline form; it consists of 2 undecylimidazoline-hydrochloride. The base liberated-in the usual manner from this'salt may be purified by recrystallization from-alcohol of 50 '-per cent. strength, whereby it is obtained in the form of colorless laminae which meltat 82 C.

Example 3 In an apparatus such as is described in Example 1 there is heated to 180 C. a mixture of Parts Oleic acid Ethylenediaminehydrate 15 the mass which at first is somewhat foamy boils finally gently as soon as the water has been distilled. After cooling to 120 C. there are added another 15 parts of ethylenediaminehydrate and heating is renewed to C. 87.5 parts of ethylenediaminehydrochloride are now added, whereupon the temperature of the mass is raised to 280 C. within 15 minutes and kept there for 10 minutes. The massis then allowed to cool to 120 C, another 10 parts of ethylenediaminehydrate are added, and the mixture is heated with- Example 4 Parts Oleic acid ethylester *10 Ethylenediaminehydrate 2 Ethylenediaminehydrochloride 3 are heated together in the manner described in 'Example'Lsave that the temperature of the mass for the saponification of the ester is allowed to remain for some time (about 5-10 minutes) at 120-1'30" C. The aqueous solution of the heptadecenylimidazoline-hydrochioride is treated with some active carbon and the free base is liberated by means of caustic soda; it is obtained in very good yield.

Example 5 8.5 parts of N-N-di-lauroylethylenediamide are heated with 3.3 parts of ethylenediaminehydrochloride in an open flask, while stirring, in such a manner that after 5-10 minutes the mixture has a temperature of about 270-280 C. The heating is continued for another 10 minutes to 280290 0., whereby the greater quantity of the hydrochloride passes into solution. A sample then dissolves clearly in water.

Caustic soda solution precipitates from the arc er? aqueous solution the undecylimidazoiine which is the product of reaction in approximately quantitative yield.

Example 6 10 parts of mono-lauroylethylenediaminehydrochloride are heated for 5-10 minutes to 260-280 C. and then for a further 5-10 minutes to 285-295 C. The hydrochloride of the undecylimidazoline is thus formed. A similar result is obtained by substituting the corresponding hydrobromide or sulfate for the mono-lauroylethylene-diamine-hydrochloride, or by using instead of the mono-lauroylethylenediamine-hydrochloride a derivative acylated with another fatty acid of high molecularweight, such as for example the mono-stearoyl-, the mono-oleoyl-, the mono-pa1mitoyl-, the mono-capryloylethylenediamine-hydrochloride, or finally by using the corresponding 1:2-propylenediamine or 2:3- butylenediamine derivatives.

What we claim is:

1. Process for the manufacture of 2-substituted imidazolines which comprises causing one mol of a product selected from the group consisting of the fatty acids and naphthenic acids to react with half a mol of a base which is substituted at two carbon atoms adjacent to each other and linked by a single bond by an amino group each, of which amino groups one contains two hydrogen atoms and the other atleast one hydrogen atom, and with half 2. mol of a salt of such a base with a strong acid, the reaction being carried out at a high temperature.

2. Process for the manufacture of 2-substituted imidazolines which comprises causing one mol of a product selected from the group consisting of the fatty acids and naphthenic acids to react with half a mol of a base which is substituted at two carbon atoms adjacent to each other and linked by a single bond by an amino group each, of which amino groups one contains two hydrogen atoms and the other at least one hydrogen atom, and with half a mol of a salt of such a base with a strong acid, the reaction being carried out at a high temperature while using an excess of the free base.

3. Process for the manufacture of 2-substituted imidazolines which comprises causing one mol of a product selected from the group consisting of the fatty acids and naphthenic acids to react with half a mol of a base which is substituted at two carbon atoms adjacent to each other and linked by a single bond by an amino group each, of which amino groups one contains two hydrogen atoms and the other at least one hydrogen atom, and with half a mol of a salt of such a base with a strong acid, the reaction being carried out at a high temperature while using an excess of the salt of the base with a strong acid.

4. Process for the manufacture of 2-substituted imidazolines which comprises causing one mol of a product selected from the group consisting of the fatty acids and naphthenlc acids to react with half 3. mol of a base which is sub stituted at two carbon atoms adjacent'to each such a base with a strong acid, the reaction being carried out at a high temperature while using an react with half a mol of a base which is substituted at two carbon atoms adjacent to each other and linked by a single bond by an amino group each, of which amino groups one contains two hydrogen atoms andthe other at least one hydrogen atom, and with half 9. mol of a salt of such a base with a strong acid, the reaction being carried out at temperatures lying between 200 and 300 C.

6. Process for the manufacture of 2-substituted imidazolines which comprises causing one mol of a product selected from the group consisting ofthe fatty acids containing 10 to 18 C-atcms to react with half a mol of a base which is substituted at two carbon atoms adjacent to each other and linked by a single bond by an amino group each, of which amino groups one contains two hydrogen atoms and the other at least one hydrogen atom, and with half a mol of a salt of such a base with a strong acid. the reaction being otherwise carried out at a high temperature;

'7. Process for the manufacture of 2-substituted imidazolines which comprises causing one mol of a product selected from the group consisting of the fatty -acids containing 10 to 18 C-atoms to react with half a mol of ethylene diamine and half a mol of a salt of ethylene diamine with a strong acid, the reaction being carried out at temperatures lying between 200 and 300 C.

mol of a product selected from the group consisting of the fatty acids containing 10 to 18 C-atoms to react with half 2. mol of ethylene diamine and half 2. mol of ethylene diamine hydrochloride, the reaction being carried out at temperatures lying between 200 and 300 C.

9. Process for the manufacture of 2-substituted imidazolines which comprises causing one mol of stearic acid to react with half 9. mol of ethylene diamine and half a mol of ethylene diamine hydrochloride, the reaction being carried out at I temperatures lying between 250 and 300 C.

10. Process for the manufacture of 2-substituted imidazolines which comprises causing one mol of oleic acid to react with half a mol of ethylene diamine and half a mol of ethylene diamine hydrochloride, the reaction being carried out at temperatures lying between 250 and 300 C.

11. Process for the manufacture of 2-substituted imidazolines which comprises causing one mol of lauric acid to react with half a mol of ethylene diamine and half a mol of ethylene diamine hydrochloride, the reaction being carried out at temperatures lying between 250 and 300 C.

EDMUND WALDMANN. a AUGUST CHWALA. 

